Test No. 26: Power Door Locks May Not Be Locked Or Unlocked When Using Power Door Lock Control Switch Or The Key
- Check wiring harness and electrical connectors for power door lock system. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Power door lock control switch may also be referred to as door lock control switch. Passenger's side Junction Block (J/B) Electronic Control Unit (ECU) is located at passenger's side of instrument panel. See Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck power door lock operation.
- Check passenger's side J/B ECU for proper voltage and input signals. See PASSENGER'S SIDE JUNCTION BLOCK ELECTRONIC CONTROL UNIT under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage and input signals do not exist, repair as necessary and recheck power door lock operation.
- Replace passenger's side J/B ECU with a known-good passenger's side J/B ECU and recheck power door lock operation. If power door locks operate properly, original passenger's side J/B ECU was defective. If power door locks still do not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU and power door locks for intermittent problem. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. Repair wiring harness or electrical connector as necessary.